The record-linkage system available for residents of Rochester, Minnesota has been used to identify all possible cases of complex partial, absence, and tonic-clonic seizures diagnosed between the years 1935 and 1979 who were born in the community. Case-control studies were conducted to identify risk factors associated with these seizure types. Several studies on convulsive disorders are being planned and tested for feasibility, or in progress. A protocol is in preparation for a clinical study of the Lennox-Gastaut syndrome (LGS), a severe childhood epileptic encephalopathy with significant morbidity and mortality, characterized by uncontrolled seizures, mental retardation, and possible mental deterioration, to define the pathophysiology and anatomic locus of disturbance in LGS. A descriptive and analytic study of neonatal seizures in a large military database is underway. Data are available for all singleton livebirths in military hospitals for a four-year period, a database including 375,310 infants. The occurrence of seizures in the nursery period in these infants and information on maternal and birth factors forms the basis for the study of these characteristics as predictors of neonatal seizures. We are evaluating the feasibility of performing a randomized and placebo controlled clinical trial of treatment after an initial convulsion in subjects presenting for care to the Beijing Tiantan Hospital.